Opposite of OLE Control "InsertFile" method

We use the olecontrol.insertFile (...) method to populate an olecontrol object with a file system document - for example, "foo.xlsx".

How can we now extract the document out of the olecontrol, and write it back into a file system document?

We know we cannot do the following, at least for complex documents such as XLSX spreadsheets:

blob    blob_objectData
int     i_rc, i_file
long    l_rc

i_rc = ole_1.insertFile ("C:\temp\foo1.xlsx")

blob_objectData = ole_1.objectdata

i_file = fileOpen ("C:\temp\foo2.xlsx", StreamMode!, Write!, LockWrite!, Replace!)
l_rc = filewriteEx (i_file, blob_objectData)
i_rc = fileClose (i_file)

Basically we are looking for something that is conceptually an "olecontrol.extractFile (...)" method. Does anyone have a suggestion on how to do this?

The real-world problem we are trying to solve is as follows: Application users embed document files such as spreadsheets in our database. How can we automate exporting these database-stored documents back into document files without having to activate each one interactively and performing a "Save As..."?

Thanks!

Comment

Load more comments

Brad Mettee
Tuesday, 6 February 2018 14:01 PM UTC

Are the OLE controls used to edit the information in any way? If not, you can read the file into a blob directly, and store that blob to the DB, without using the OLE controls at all.

You may also want to try a binary compare of an original file to the ole_1.objectdata version, so you can see if there's any way to strip off the header before writing the file out (by using blobmid or similar).

Helpful 0

Dan Harrel
Tuesday, 6 February 2018 16:05 PM UTC

Indeed the OLE controls are used to edit the information, and then store the edited information back into the database. Otherwise, you are correct, we could just write the Excel binary into the database, and then retrieve it, write it to a temporary file, and launch.

I think we tried a binary compare and it was not so clear cut how to strip off the "OLE stuff", but I will look again.

I wish this all were easier (i.e. opposite of ole_1.insertfile (...)), but it appears not to be.

That said - I found one product out there that may do the trick: http://www.yohz.com/sbv_details.htm

Thanks!

Dan Harrel
Wednesday, 14 February 2018 19:29 PM UTC

Hi Rene,

We are trying your suggestion with incomplete success, and hope you can help further.

If we "insertfile" an XLSX spreadsheet into an OLE control ole_1, and then do the following:

oleobject obj_oleobj

obj_oleobj = ole_1.object

// 51 = (without macro's in 2007-2016, xlsx)

b_rc = obj_oleobj.saveas ("c:\temp\bla.xlsx", 51)

We get a file "c:\temp\bla.xlsx" that, when double-clicked, starts up Excel, but shows as blank. A lighter excel viewer will show us the spreadsheet contents.

What we are actually doing, however, is after "insertfile" an XLSX spreadsheet into ole_1, we write ole_1.objectdata into a blob database column.

Later, we selectblob the database value into blob_foo, and then:

oleobject obj_oleobj

ole_1.objectdata = blob_foo

obj_oleobj = ole_1.object

// 51 = xlOpenXMLWorkbook (without macro's in 2007-2016, xlsx)

b_rc = obj_oleobj.saveas ("c:\temp\bla.xlsx", 51)

However the "saveas" verb now produces an error.

Any insights you have would be appreciated into:

1) Why the first code block produced a XLSX file that seemed to be accepted by Excel but did not display

2) Why the second code block did not behave the same as the first. (is "obj_oleobj = ole_1.object" OK and usable for automation verbs?).

Thanks,

Dan.

There are no comments made yet.

Resolved Opposite of OLE Control "InsertFile" method